Message-ID: <41AB74CB.5050805@metatrontech.com>
Date: Mon, 29 Nov 2004 11:13:15 -0800
From: Chris Travers <chris@metatrontech.com>
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To: Jonathan Knopp <pgsql@delegated.net>, pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: Way to stop recursion?
References: <41A79A2A.6070606@delegated.net> <19345.1101504671@sss.pgh.pa.us>
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Jonathan Knopp wrote:

>
> Sorry, I should have mentioned that there is a lot more to the design 
> that makes this replication necessary, including another two levels to 
> the tree plus the ability to have orphaned children.
>
My first thought was "Dude, use a VIEW...."

In database design, the SPOT principle applies.  *Always* enforce a 
Single Point Of Truth.  If that doesn't seem to be possible, rethink how 
the data is used and look at how to ensure that there is only ONE 
authoritative storeage for each piece of transactional data. (Yes, 
sometimes we get away from this with OLAP installations but the data is 
not generally being updated there.)

In this case, I would create a view (with appropriate rules) which would 
automatically populate the common fields from the parent if it exists.  
The issue should not be one of storage but of presentation.

Best Wishes,
Chris Travers
Metatron Technology Consulting

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